Ok guys, this should not be happening, but it is. Heres whats up. Car ran perfectly when put away for the winter, no problems. Swapped the upgraded Vortecs on a few weeks ago, and performer intake.
When I start it up, immediatly there is this knocking like sound. Now I went through this before with the 305, pulled it and it was a spun bearing. This sounds a little different. Sounds hollow, almost like its detonating in the headers. As far as I know, there should be no reason whatsoever why it would have spun a bearing or have a rod knocking, I bought the engine new last summer from SDPC, and drove it half a summer and put it away. I've checked everything over and over, valve lash was set cold at 1/2 turn past 0 lash. Everything sealed. Cam and everything else is in sig. I pulled the pulleys for water pump, PS and alternator, nothing (I was hoping my water pump went out). Checked spark wires again, all are in correct order.
My starter sounds like its starting to go, its weak. Was thinking possibly the engaging gear is sticking and that might cause it but I'm thinking not now. Anything else.....oh, pulled valve covers and ran it, thinking maybe valves hitting on them, nope. Regular spark plugs should work with the Vortec heads, right? Cause I'm using my accel header plugs. Pretty much, I've looked over everything, cant seem to figure it out. Pulled my new billet dipstick out, checked oil, level was a bit low, but when running it showed about 40psi on my gauge. Oh ya, it is about 1:1 with my engine timing, it varies with RPM.
Can anyone throw out any ideas here? This should not be happening.
Thanks,
Ben

 

you shouldn't be having any mechanical problems, one thing i thought of was old fuel.

 

dont know if thisll help, but i had a 69 torino that did that couldnt figure it out.so i figured it was timing since i knew it wasnt a bearing.ended up didtributor was worn out.

 

old fuel could defently do it.. my car runs like total **** after sitting for a few months... after puttin new gas in its fine....

 

Well my friends, I'll tell you what. Was out there right after posting this, trying to figure things out. Thinking through EVERYTHING that could possibly be wrong. Well, I thought MAYBE I dropped a bolt/nut or somehting in one of the bores when swapping heads (even though I was really careful and taking my time) but hey, stuff happens right? Well, pulled all my spark plugs out and checked them to see if something was smashing around in the chambers, but not a scratch on any of plugs.
Before that, one of my friends came by and listened to it, stumped him too, but he mentioned it may be bad gas. After thinking about it some (and after ripping the plugs and wires out, and starting to dissasemble the motor yet AGAIN), I remembered that I didnt have the pump or anything hooked up this whole winter, meaning the gas line was basically open to the air and tank. I'd think that being NOT sealed like that could have an effect on the quality of the gas. I specifically remember when I plugged my pump in to test it out before installing, with the line hooked up, it pumped out some pinkish-looking gas. And now that I think about it even more, I cant keep my car running. See I rebuilt the ccQjet this winter at home in my apartment, taking my time and doing it right. Did everything to specs, but it still wont stay running and has a little hard time firing up. Thought maybe it was out of whack, and cant really adjust it till its running right? This all makes a little sense. If bad gas really can have that effect directly on the engine and make it knock, I'm willing to bet thats what it is. Wow, I really hope its something that simple.

Oh ya, when it woudlnt stay running, I have to keep pumping the pedal to keep it running, but it always wants to stall out. Sound like this could be my problem??

I'll reinstall the plugs and wires and drain my gas, and add new gas and test that out ASAP, but I dont know if it will happen this weekend, I've already completely destroyed my Saturday by trying to diagnose this problem. Man, I was hoping to have it runnign perfect and starting my shift kit install!

 

Forgot, Thanks for the quick replys guys. Really helps out, both in solving my problem(s) AND giving me a little bit of piece of mind, knowing that it could be something more simple!

 

Bad gas can equal detonation...which could have been the noise. Let us know.

 

Anyone else want to chime in?

 

Well, I emptied the tank, dumped in about 6 gallons of new gas, hooked the line back up and primed the line. I also reinstalled the plugs and wires and then tried to start the car. Would crank over, and try to fire, but i could not get it to start. It would run for about 2 seconds at about 500rpm, then stall out. Can't figure this out. I thought it might be flooded, tried holding the choke flap opened and did the same. Pulled a plug, but it was bone dry. I think I'm having carb problems here.
I am assuming a huge lean condition could cause bad running (obviously) but also a hard knocking, am I correct?
I am going to tear apart the carb tonight and take a look at it. I might build one of my other ones also, so I have two to work with next time I go home.
Oh, I know the accelerator pump worked because I could rotate the throttle shaft and see that it would squirt gas into the body. I am thinking tho that maybe something is wrong with the idle circuits or something is plugged up somewhere. Since the pump works, Im thinking that there should not be a problem with the float bowl being stuck or anything like that. I guess we'll see.

 

Ok, no one has replied. Well, I took the carb apart, and lo and behold, two of the holes (not sure what they are for exactly, I'm hoping someone can clarify that for me?) are plugged up. You cannot tell in the pic, but there is a bunch of sand-like stuff in the holes, and cannot be blown through.
Can someone answer my previous question, and let me know if this would affect the car running. When I came home this weekend, it ran, but not very well, and it kept gettin worse, only running for even shorter spurts of time, less and less each time I tried to run it. I'm thinking this sand just kept clogging the holes more each time I ran it.

 

Forgot pic.

 

After further disassembling the carb, I found out that I did not install the spring where the check ball is (in the bottom of the float bowl). I'm not sure what that is for either, but my guess again is that this would affect how it ran. Anyone?

 

See atatched pic, red.

 

More of teh bad gas issue. The bad gas will stick up any thing in a carb. Especially if teh carb sat on the car all winter without being run. Then once you add the new gas it loosens up more and more of teh varnish clogging air bleeds , idle jets etc..... Once you rebuild the carb, I would install an inline fuel filter on both the tank side and carb side of teh pump. You should be looking pretty after that.....

 

Thanks littlebagz.

Can anyone comment on my previous questions?

 

No one knows what those holes are for...I cant hardly believe that.

I know theres guys, or possibly gals, on here that know Qjets enough to know what those holes/spring and checkball are for...

Please? I'd really like to know.

 

Just wanted to top off this thread by informing everyone what happened, in case anyone was interested. Come to find out, someone had jacked up my car and must have had the jack under the steering rod that runs under the oilpan. Well, it bent the oilpan up and the crank was hitting on it. Took a good chunk of my day to pull the pan and fix it, but now its running and no more knock!

 

whats the steerin rod that runs under the oil pan???????

 

That would be the center link... I actually had a floor jack slip off of the crossmember one time and the center link caught it (whew! better than the oil pan! )... One of those little padded jacks would slip between the center link and the crossmember and punch the oil pan though...

 

The holes that you have circled are part of the main metering system. IIRC they control transition (part throttle) metering. The other ones ar ethe idle air bleeds. I may have them backwards. In either case, having them plugged will create massive driveability issues; stumbling, lean or rich running, etc.

The check ball is on the discharge side of the accelerator pump, such that when you open the throttle, the fule being pumped lifts it off of the seat. Without it, the pump discharge nozzle can actually behave like a little discharge nozzle at sustained high RPMs, and feed extra fuel by siphoning it through the accel pump circuit.

Make sure there's a fuel filter in the inlet nut. Go get a new one, and remove the rubber valve thing from out of it before installing it.

 

Sorry this thread is getting old, just have one quick question. I searched but didnt find anything related. Concerning the check ball, can anyone tell me if there should be a spring between the screw and the ball? The diagram in the rebuild kits do not show anything, but I seem to have a spring that goes there? Anyone know?

Thanks again.